FIG. 1 is an anatomic view of a healthy tooth. The tooth includes a crown and a root. The root is encased by a supporting ligament in alveolar (jaw) bone. The ligament comprises a tough band of shock-absorbing connective tissue, which physically binds the tooth root to the jaw bone. The hole occupied by the tooth in the bone is called the tooth socket.
The crown of the tooth is exposed above the gum. A hard shiny outer surface, called the enamel, covers the crown. Below the enamel is dentin, which is microscopically porous hard tissue. At the center of the tooth is the pulp chamber, which houses the pulp consisting of blood vessels and nerve tissues.
A tooth may become damaged, or decayed, e.g., due to erosion of the calcium in the tooth's enamel by bacteria. This, in turn, can lead to erosion of the dentin beneath the enamel. As the decay continues, bacteria can migrate through the porous dentin and infect the pulp. An immune response to the infection can follow, causing the blood vessels around the tooth to enlarge and press against the nerves entering the tooth. The result is tooth ache.
There are various dental procedures for intervening when these or other conditions affecting the oral cavity and its anatomic structures arise. These procedures are routinely performed by dentists including general practitioners, oral and maxillofacial surgeons, endodontists and periodontists.
For example, endodontic therapy, also called root canal therapy, can, under many circumstances, intervene to remove the bacteria, nerve tissue, organic debris, and bacterial toxins from within the inner aspects of a decaying tooth. Following this, the practitioner fills in and seals off the interior of the tooth. Currently, there are about 16 million root canals performed annually in the USA.
If the decay has progressed too far, removal or extraction of the tooth may be indicated. Currently, there are more than 30 million extractions performed each year in the USA. During a simple extraction, a dentist will grasp the tooth with an instrument, e.g., forceps, and rock the tooth back and forth. This rocking motion loosens the tooth from the alveolar bone by breaking the periodontal ligaments that hold the tooth in place. The tooth is then extracted from the socket, leaving the tooth socket open.
Removal or extraction of the tooth may also be indicated when the presence of the tooth is causing crowding, or malocclusion, or preventing another tooth (e.g., a wisdom tooth) from erupting, or in preparation for orthodontic treatment (“braces”). A tooth extraction may also be indicated because of advanced periodontal (gum) disease. Sometimes, if the tooth selected for extraction is not fully erupted above the gum, it may be necessary to first remove some of the overlying gum and bone tissue in order to access the tooth for extraction.
During and after such conventional dental procedures—e.g., endodontic surgery, or periodontal surgery, orthodontic treatment, tooth extractions, orthognathic surgery, biopsies, and other oral surgery procedures—bleeding, fluid seepage or weeping, or other forms of fluid loss typically occur. Bleeding, fluid seepage or weeping, or other forms of fluid loss can also occur in the oral cavity as a result of injury or trauma to tissue and structures in the oral cavity. In this regard, there are about two million teeth lost each year due to accidents. Swelling and residual bleeding can be typically expected to persist during the healing period following the procedure or injury. During the healing period, new gum tissue will grown into the gap left by the extraction.
It is thereby desirable during the healing period to take steps to stanch, seal, and/or stabilize the site of surgical intervention—or the site of tissue injury or trauma—against fluid loss due to bleeding, fluid seepage or weeping. During and after dental procedures or injury to the oral cavity, there is a need for quick and effective hemostasis.
For example, following a tooth extraction, the quick cessation of bleeding and the formation of a blood clot on the wound in the open tooth socket are very desirable. Indeed, during the entire healing period following an extraction—which can take from one to six weeks—it is important to preserve conditions conducive to hemostasis, so that the blood clot that forms within the socket does not break down and/or dislodge. If the clot breaks down and/or dislodges, a condition known as a dry socket (also called alveolar osteitis) results. Dry socket conditions can also occur for the same reason during the treatment of cystic cavity defects in the jaw. Dry socket can cause pain and discomfort, which will subside only as the socket heals through a secondary healing process.
Conventionally, cotton packs and rolled or folded cotton gauze pads are commonly used to stem the bleeding precipitated during and after dental procedures. While the presence of such materials may absorb blood and fluids, they do not promote or create conditions conducive to rapid and long term hemostasis or healing. There still remains a need for improved hemostatic compositions, assemblies, and methods that can be applied during or after dental procedures.
Along with damage to the tooth itself, there may also be damage to the gums and gingival material surrounding the tooth or teeth. For example, people may have problems associated with inadequate amounts of gingival material surrounding a tooth or teeth. If there is inadequate attached gingiva, spontaneous recession of the gum and bone will occur over time. Typically the normal attached gingiva has been worn away with improper brushing, although some people are born with very little attached gingiva.
Surgeries are performed on these areas to provide added gingiva to the area, typically by adding a gingival graft from another area located in the person's mouth. These procedures are frequently performed, yet they are also some of the most sensitive surgical wounds that must be managed by periodontists. Post operative pain, recurrent bleeding, delayed secondary healing, associated with these types of wounds and the open nature of these wounds all contribute to the problematic post operative issues associated with these types of wounds. Treatment generally has been done using protective stents and/or periodontal dressings placed over the wound area, but these treatments do not necessarily promote hemostasis and secondary healing for the wound site as effectively as desired. Consequently, there has been a long felt need for processes and assemblies that can be used to promote hemostasis, enhance blood clot stability after surgery and shorten healing times.